Non-conventional searches at the LHC (IBS-CTPU Focused workshop)

14 Dec 2015, 08:00 → 18 Dec 2015, 12:30 Asia/Seoul

IBS-CTPU

The Synergy from collaborations between theorists and experimentalist in the BSM searches

With TeV Energy scale collider experiments, we are facing unexpected difficulties in the search of the physics beyond the Standard Model, mostly coming from uncertainties in the behavior of QCD. We are also limited to a finite number of modelings of BSM through conventional searches at the LHC. 

So far, searches motivated from CMSSM, Simplified models, crossing with Dark matter direct searches (mono-X) have been populated in HEP society. But Collider searches should not be restricted by models that we know well about. 

Challenges from TeV Energy scale phenomena can be solved only based on the intensive discussions between BSM theory community and experimental collaborations.

This focused workshop is designed to boost synergy from collaborated efforts between HEP-PH and CMS/ATLAS groups, and to maximize the chance of discoveries with Future colliders including the LHC. 

Our main topics to be discussed are following, 

• Search strategies in BSM hunting
• Issues of non-conventional signatures (and related BSM) at Colliders
• Reducing corruptions from QCD activities
• Adapting Monte Carlo simulations to non-conventional searches

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Invited speakers : 

• HEP-PH
  • K.C. Kong (University of Kansas)
  • Hyun Min Lee (Chung-Ang University)
  • Seung J. Lee (Korea University)
  • Ian Lewis (SLAC)
  • Adam Martin (University of Notre Dame)
  • Seongchan Park (Yonsei Unversity)
  • Jeonghyeon Song (KonKuk University)
  • Felix Yu (University Mainz)
  • Yuhsin Tsai (Maryland University)
  • Doojin Kim (University of Florida)
  • Ken Mimasu (University of Sussex)
  • Chengcheng Han (Kavli IPMU)
     
• HEP-EX
  • Jae-Hyeok Yoo (CMS, UC Santa Barbara)
  • Enrique Kajomovitz (ATLAS, Duke University)
     
• HEP-MC​
  • Nicolas Greiner (University of Zurich)

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Organizers 

• Myeonghun Park (chair, IBS-CTPU)
• Hye-Sung Lee (IBS-CTPU)
• Hwidong Yoo (Seoul National University)
• Sezen Sekmen (Kyungbook National University) 

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Sponsored by

  

Monday, 14 December

Plenary Session

1 Introduction

Speaker: Dr Park Myeonghun (IBS-CTPU)

2 New directions in SUSY searches

This talk will focus on the topic of new directions in SUSY searches and discuss new ideas about how to search for SUSY at LHC.

Speaker: Dr Seen Sekmen

Slides SekmenBrusselsNewDirSUSY151113.pdf

Lunch

Plenary Session

3 The Coannihilation Codex

We present a general classification of simplified models that lead to dark matter (DM) coannihilation processes of the form DM + X $\rightarrow$ SM$_1$ + SM$_2$, where X is a coannihilation partner for the DM particle and SM$_1$, SM$_2$ are Standard Model fields. Our classification also encompasses regular DM pair annihilation scenarios if DM and X are identical. Each coannhilation scenario motivates the introduction of a mediating particle M that can either belong to the Standard Model or be a new field, whereby the resulting interactions between the dark sector and the Standard Model are realized as tree-level and dimension-four couplings. We construct a basis of coannihilation models, classified by the $SU(3)_C \times SU(2)_L \times U(1)_Y$ quantum numbers of DM, X and M. Our main assumptions are that dark matter is an electrically neutral color singlet and that all new particles are either scalars, Dirac or Majorana fermions, or vectors. We illustrate how new scenarios arising from electroweak symmetry breaking effects can be connected to our electroweak symmetric simplified models. We offer a comprehensive discussion of the phenomenological features of our models, encompassing the physics of thermal freeze-out, direct and indirect detection constraints, and in particular searches at the Large Hadron Collider (LHC). Many novel signatures that are not covered in current LHC searches are emphasized, and new and improved LHC analyses tackling these signatures are proposed. We discuss how the coannihilation simplified models can be used to connect results from all classes of experiments in a straightforward and transparent way. This point is illustrated with a detailed discussion of the phenomenology of a particular simplified model featuring leptoquark-mediated dark matter coannihilation.

Speaker: Dr Felix Yu

Slides Felix.pdf

4 Searching for new physics with Voronoi tessellations

High energy experimental data can be viewed as a sampling of the relevant phase space. We point out that one can apply Voronoi tessellations in order to understand the underlying probability distributions governing the relevant phenomena. Characteristic features embedded in the data can then be discovered by studying the properties of Voronoi cells. We particularly focus on detecting kinematic "edges", taking the examples of two- and three-dimensional data for concreteness. To this end, we propose algorithms motivated by some analytic results derived for perfect lattices, and show that the relevant methods can be further improved with the addition of a few Voronoi relaxation steps via Lloyd's method.

Speaker: Dr Doojin Kim

Slides Presentation_DoojinKim_IBS2015.pdf

Break

Talks

5 Capturing soft signatures @LHC

Speaker: Dr Chengcheng Han (Kavli IPMU)

Discussion

Tuesday, 15 December

Plenary Session

6 Searching for high mass Diboson Resonances in ATLAS

High mass diboson resonances appear in many extensions to the Standard Model. The large dataset of 8 TeV pp collisions collected during the first run of the LHC allowed us to search for these resonances at the TeV scale for the first time. In one of these searches performed by the ATLAS experiment, a small but nevertheless intriguing excess over the background expectation is seen in the region around 2 TeV. We will discuss the ATLAS searches and their corresponding results in detail, including an extended discussion on the techniques used to achieve sensitivity. We will also discuss plans for these searches with the early data from the second run of the LHC.

Speaker: Dr Enrique Kajomovitz

7 A Consistent Model for Strongly Interacting Massive Particles

Speaker: Prof. Hyun Min Lee

Slides ibs2015-hmlee.pdf

Lunch

Plenary Session

8 Looking for Resonances under the LHC Lamppost

Speaker: Prof. Kyoungchul Kong

9 BSM physics with GoSam

Speaker: Dr Nicolas Greiner

Break

Talks

10 Probing TeV Scale New Resonances with Jet Substructure Methods

Speaker: Mr Jeong Han Kim (KAIST)

Slides IBS_CTPU_14th_Dec_2015.pdf

11 Real and Imaginary interference for a heavy Higgs boson

Speaker: Prof. Jeonghyeon Song (KonKuk University)

Discussion

Banquet

Wednesday, 16 December

Plenary Session

12 Conventional and Unconventional SUSY Searches at CMS : Results from the new energy regime, √s=13 TeV

The LHC has resumed its operation at the new energy regime, √s=13 TeV, which we had never been before. Thanks to the higher energy compared to the Run1, the cross sections for the production of very heavy objects increased dramatically. This brings a huge advantage to the SUSY searches at the LHC. The CMS carried out some of the conventional SUSY searches using the new data and their results will be discussed in the first half of the talk. In addition, a new analysis has been performed using the scalar sum of masses of the large-radius jets. The rest half of the talk will discuss this analysis in detail.

Speaker: Dr Jae Hyeok Yoo

Slides Jae_CTPUworkshop_16Dec2015.pdf

13 Techniques for finding electroweakinos

Speaker: Prof. MARTIN Adam

Slides amartin_ewinos.pdf

Lunch

Plenary Session

14 The Quantum Critical Higgs

Speaker: Prof. Seung Joon Lee (Korea University)

Slides Daejeon_December_2015_SJLEE.pdf

Talks

15 Threshold corrections at third order in QCD for Higgs production at the LHC

Speaker: Mr Manoj Mandal

16 Signals of vectorlike leptons in a heavy Higgs cascade decay

Speaker: Dr Seodong Shin

Slides Seodong.pdf

Break

Discussion

Thursday, 17 December

Plenary Session

17 New Physics Under the Higgs Lampost

WIth the discovery of a Higgs boson, the Standard Model of particle physics is complete. Due to its nature as the source of electroweak symmetry breaking in the Standard Model and its loop induced production at hadron colliders, measurements of the HIggs boson can provide particular insight into beyond the Standard Model physics. In this talk I will give an overview of what can be learned from these measurements, with a particular focus on double Higgs and Higgs plus jet production.

Speaker: Prof. Ian Lewis

Slides IL_IBS_2015_Ian.pdf

18 Exotic Signals in Twin Higgs Model

Twin Higgs (TH) model gives a naturalness motivation to study the non-colored BSM particles, which usually have decay processes relating to the dark-hadronization and displaced signal. In this talk, I will use the exotic twin-quarks to discuss the search of these decays. The exotic-quarks play a vital role in UV completing the TH model, and their decay products contain both SM particles and twin-hadrons, including twin-glueballs, mesons, and leptons. These twin-objects decay displacedly into SM b-quarks or leptons, and the striking signal allows the reach of twin UV-physics at the LHC and future collider. Interesting complimentarily constraints between collider and astrophysical search will also be discussed.

Speaker: Dr Yu Hsin Tsai

Slides Exotic_twin_qaurks_IBS.pdf

Lunch

Talks

19 The hierarchical two Higgs doublet model: probing the electroweak phase transition at the LHC

Speaker: Dr Ken Mimasu

Slides Mimasu_non_conventional.pdf

20 Searching for Di-Higgs Production via Topological Augmentation

Speaker: Dr Wonsang Cho

Break

Discussion

Friday, 18 December

Discussion

Lunch